Kiln



UNITED STATES FRANCIS FIDIIER, 0F WIGAN,

LANCASHIRE, AND JAMES GRAHAM MAXWELL, O LONDON, ENGLAND.

KILN.

Specification of Letters Patent.

Patented Jan.4, v1921.

Applicationled December27, 1919. Serial No. 347,679.

To all 'whom it may concern Be it known thatwe, FRANCIS FIDLER and JAMES GRAHAM' MAXWELL, subjects of the King of Great Britain and Ireland, ,residing at Wigan, Lancashire, England, and London, England, respectivel have invented certainv new and useful Improvements ,in Kilns, of which the following isaspecification.

This invention relates to improvements in kilns of the tunnel and car type. l

In the specification ofour coependin'g application Serial Number 347,699 iiled on even date herewith means are described for .extracting heat from the cooling zone of a tunnel and car kiln by the aid of air currents which do not make contact with the wares or goods in the cooling tunnel or cooling zone as it is called, so that cracking of the burnt goods is prevented, the heat extracted by the air currents being rendered available for use in any convenient .apparatus. I l One object of the present invention is to enable this heat to be utilized effectively in drying tunnels or chambers. f

Another object of the invention is to enable the waste gases of combustion from the burning zone and preheatingzone to be applied to'the heating of the dryingtunnels or chambers in such a way that they do not make direct IContact with the green ware or goods therein, thereby preventing liability to discoloration by reasonpof the gases 'containing the products of combustion.

In the accompanying drawings f Figure l is a lplan partly in section, of

one form of tunnel and car kiln with drying tunnels, according to the invention, the sections of the drying tunnels, being taken on the'lines I-I vand I-I Fig. 2.

Fig. 2 is an end sectional lelevation of a drying tunnel on a larger scale, thel section being taken on IIMI'I Fig-1.

Fig. 3 is a side 'sectional eleva-tion on the line III-III Fig. 2.

Fig. 4 isa sectional plan on I- I`Fig. 2.

Figs. 5 andv 6 are respectively a sectional elevation and sectional plan of part of a vent shaft or, chimney, vthe sections being taken respectively on the lines V-V and VI-VI.,

` ,absorbers 11Figi. 7 is a sectional elevation on VII-VII n the form illustrated, the'tunnel and car kiln comprises a preheating `zone 1, u burnlng zone 2, and a coolin zone 3, the three zones together being in a inement and forming a single tunnel through which the goods or ware travel on cars vin the manner well known in the art. `The kilnalso comprises two drying tunnels 24, 24, fitted with tracks 38 for cars 39 .to be vrun through the tunnels 24 so that the greenware or goods may be dried before being passed into thel preheating z one l. A The cooling zone 3 is provlded with air ducts in its structure for the purpose of extracting heat "from the Ware or goods therein by means of air which doesA not make direct contact with said goods. In order that the air may absorb heat readily the ducts are separated from the interior of the tunnel by good heat conductive material.v Particular constructions of these-ducts are described in our co-pending application above noted -filed on even date herewith. For the sake of simplicity in the present specification they are indlcated as zig-zag ducts 7 separated from the interior of the tunnel by panels of cast iron or other heat conductive material. These panels 7 form 'heat absorbers and the air passing through the ducts 7 impinge on' the 7 and extract heat therefrom. ,Air is passed through the ducts 7 by. suitable means such as fans. The air after extractpasses from the pipes 23 directly through slots 43 into the tunnels, and after passing through the tunnels in contact .with the warel or,goods is extracted through openings 44 together with the moisture given off by the green'ware or goods, the extraction being effected by suitable -means such as fans delivering the extracted air and moisture into vents or chimneys. Branch pipes 40.l fitted with stop cocks 41 are alsov provided so that the clean hot air from the ducts 7 may be led into ducts 42 in the roofs of the drying tunnels 24 and thence through the slots 43 into the interior of the tunnels 24.

The drying tunnels 24 also have gas ducts or iues in their structure for the passage of hot gases of combustion for indirect heating of the green goods or wares forexample vertical ducts 44 `are connected alternately at the upper and lower ends by horizontal ducts 45, 46. The. ducts 44 are separated from the interiors of the tunnels 24 by Inaterial of good heat `conductive-quality suolil as cast iron panels 47. Hot gases of combustion from the burning' zone 2 pass along the preheating zone 1 ythence by pipes 48 into the ducts 44, 45,v 46,escaping therefrom into lues or ducts 49, 50 beneath the Hoor 5l and finally being discharged by the fans through the pipes to the vents or chimneys The oors 5l are of heat conductive Ina--4 terials so thatnot only does heat from the gases pass through the panels 47 but also through the floors 51 th'e heat being radiated by the panels 47 to the green goods and being conducted to the air in the tunnels by both the panels 47-and floors 51.

Thecombustion gases are dirty or of a chemical composition likely to be deleterious to the goods but While their heat is utilized in drying the goods they are kept out ofcontact with them. A

vT he vents or chimneys 52 are preferably fitted With means for preheating air which may be utilized in any way desired for instance in the blast pipe of gas producers supplying gas to the burning zone 2. For example the vents or chimneys 52 are fitted with iron cylinders 53 provided with bailes 54 which together with the brickwork strucheat of said zone of relatively hig heat conductivity, and a means of communication between said ducts and the interiorof the drying tunnel.

2. A tunnel and car kiln having a dry` ing tunnel provided with air `ducts in its structure, said ducts being separated from the interior of said drying tunnel by good heat conductive material, and means for delivering waste gases of combustionfromthe kiln into said ducts, substantially as and for i the purpose hereinbefore set forth.

3. A tunnel and car kiln comprising a -drying tunnel a preheating zone, a burning the air ducts in the structure of the coolingl `Zone to the interior of the drying tunnel,

` and means for conducting waste gases of combustion from the burning zone and preheating zone to the ducts in the structure of the drying tunnel, substantially as and for the purpose hereinbefore set forth.

4. A tunnel and car kiln comprising a drying tunnel', a preheating zone, a burning zone and a cooling zone, said drying tunnel and cooling zone both having ducts in their structures, means Ifor connecting the ducts in the structure of the cooling zone to the interior of the drying tunnel, means for connecting the preheating zone and burning zone to the Iducts in the structure of the drying tunnel, and means for extracting the gases and moisture from the interior of the drying tunnel, substantially as and for the purpose hereinbefore set forth.

5. A tunnel and car kiln comprising a drying tunnel,`a preheating zone, a burning zone` and a. ycooling zone, said drying tunnel and cooling zone both having ducts in the walls of their structures and separated from the interior` in each case by heatrconductive mate-rial, said drying tunnel also having a duct in its crown communicating with the interior of the dryingy tunnel at one end, means for connecting said ducts in the walls of the cooling zone tothe said duct in the crown of the drying tunnel, and means for connecting the interior of the preheating zone, burning zone and cooling zone to the said ductsin the walls of the drying tunnel, substantially as and for the purpose hereinbefore set forth. I 6. A tunnel and car kiln comprising a drying tunnel, a preheating zone, a burning zone, and a cooling zone, said cooling zone and drying tunnel both having ducts in their structures, means for passingl air through the duc-ts in the structure of the cooling zone and thence through the. interior of the drying tunnel, means for eX- .tracting gases of combustion from the burning and preheating zones and for passing said gases through the ducts in the structure of the drying tunnel, and means for extracting the said air and gases from the said ducts and interior of the drying tun-4 nel, a vent shaft for receiving said .gases and air, air ducts surrounding said vent shaft for thel passage of fresh air to be heated by the waste heat of the gases and air passing through said vent shaft, substantially as and for the purpose hereinbefore set forth.

7. A drying tunnel for kilns having zigtive materialv separating said ducts from' substantially as and for the purpose here- -the interior of the tunnel, means for forcinbefore set forth. ing air through said ducts to absorb heat In testimony whereof We have signed our from the articles beingI dried, and means for names to this specication in the presence 5 utilizing such heated air beyond the tunnel. of two subscribing Witnesses.

8. A drying tunnel havingvduets in the FRANCIS FIDLER. Walls thereof, cast iron panels separating' J.' GRAHAM MAXNELL.

said lues from the interior of said tunnel, Vitnesses: 4 and means for passing hot gas through FREDL E. SQUIRE, 1Q said ues to make Contact withsaid panels, J. CLARK. 

